The present invention relates to an inflator which generates gas for inflating and deploying an air bag for protecting a vehicle occupant. In particular, the present invention relates to an air bag inflator suitable for an air bag for protecting a side of an occupant on a seat, which is improved in allowing the air bag to be held in its deployed state for a relatively long period of time by virtue of a plurality of high-pressure gas chambers.
An air bag inflator having a plurality of combustion chambers containing gas generating agents therein is known in U.S. Pat. No. 5,219,178 and Japanese Patent Unexamined Publication (KOKAI) No. H09-136604. In the air bag inflators disclosed in these publications, the volume of gas to be generated can be controlled in several modes thereby enabling the preferred deployment of the air bag to suitably correspond to the severity of the collision and the condition of the occupant.
An air bag inflator having a plurality of separate and sealed high-pressure gas chambers is also known, e.g. Japanese Patent Unexamined Publication (KOKAI) No. H07-156741.
However, there is a strong demand for an air bag inflator which can be manufactured at a low cost and enables the air bag to be held in its deployed state for a relatively long period of time.
The present invention has been made in order to satisfy the aforementioned demand, and an object of the present invention is to provide an air bag inflator, which can provide improved ability in protecting an occupant.
Another object of the invention is to provide an air bag inflator which can inflate the air bag quickly and keep the inflated condition of the air bag for a relatively long period of time.
Further objects and advantages of the invention will be apparent from the following description of the invention.